Android端流式布局
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2022-07-05 09:33:58
public class SearchFlowLayout extends ViewGroup { public SearchFlowLayout(Context context) { super(context); } public SearchFlowLayout(Context context, AttributeSet attrs) { super(context, attrs); } public SearchFlowL...
public class SearchFlowLayout extends ViewGroup {
public SearchFlowLayout(Context context) {
super(context);
}
public SearchFlowLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
public SearchFlowLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// super.onMeasure(widthMeasureSpec, heightMeasureSpec);
//遍历去调用所有子元素的measure方法(child.getMeasuredHeight()才能获取到值,否则为0)
measureChildren(widthMeasureSpec, heightMeasureSpec);
int measuredWidth = 0, measuredHeight = 0;
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int widtMode = MeasureSpec.getMode(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
//由于计算子view所占宽度,这里传值需要自身减去PaddingRight宽度,PaddingLeft会在接下来计算子元素位置时加上
Map<String, Integer> compute = compute(widthSize-getPaddingRight());
//EXACTLY模式:对应于给定大小或者match_parent情况
if (widtMode == MeasureSpec.EXACTLY) {
measuredWidth = widthSize;
//AT_MOS模式:对应wrap-content(需要手动计算大小,否则相当于match_parent)
} else if (widtMode == MeasureSpec.AT_MOST) {
measuredWidth = compute.get("allChildWidth");
}
if (heightMode == MeasureSpec.EXACTLY) {
measuredHeight = heightSize;
} else if (heightMode == MeasureSpec.AT_MOST) {
measuredHeight = compute.get("allChildHeight");
}
//设置flow的宽高
setMeasuredDimension(measuredWidth,measuredHeight);
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
for (int i = 0; i < getChildCount(); i++) {
View child = getChildAt(i);
Rect rect = (Rect) getChildAt(i).getTag();
child.layout(rect.left,rect.top,rect.right,rect.bottom);
}
}
/**
* 测量过程
* @param flowWidth 该view的宽度
* @return 返回子元素总所占宽度和高度(用于计算Flowlayout的AT_MOST模式设置宽高)
*/
private Map<String, Integer> compute(int flowWidth) {
//是否是单行
boolean aRow = true;
MarginLayoutParams marginParams;//子元素margin
int rowsWidth = getPaddingLeft();//当前行已占宽度(注意需要加上paddingLeft)
int columnHeight =getPaddingTop();//当前行顶部已占高度(注意需要加上paddingTop)
int rowsMaxHeight = 0;//当前行所有子元素的最大高度(用于换行累加高度)
for (int i = 0; i < getChildCount(); i++) {
View child = getChildAt(i);
//获取元素测量宽度和高度
int measuredWidth = child.getMeasuredWidth();
int measuredHeight = child.getMeasuredHeight();
//获取元素的margin
marginParams = (MarginLayoutParams) child.getLayoutParams();
//子元素所占宽度 = MarginLeft+ child.getMeasuredWidth+MarginRight 注意此时不能child.getWidth,因为界面没有绘制完成,此时wdith为0
int childWidth = marginParams.leftMargin + marginParams.rightMargin + measuredWidth;
int childHeight = marginParams.topMargin + marginParams.bottomMargin + measuredHeight;
//判断是否换行: 该行已占大小+该元素大小>父容器宽度 则换行
rowsMaxHeight = Math.max(rowsMaxHeight, childHeight);
//换行
if (rowsWidth + childWidth > flowWidth) {
//重置行宽度
rowsWidth = getPaddingLeft()+getPaddingRight();
//累加上该行子元素最大高度
columnHeight += rowsMaxHeight;
//重置该行最大高度
rowsMaxHeight = childHeight;
aRow = false;
}
//累加上该行子元素宽度
rowsWidth += childWidth;
//判断时占的宽段时加上margin计算,设置顶点位置时不包括margin位置,不然margin会不起作用,这是给View设置tag,在onlayout给子元素设置位置再遍历取出
child.setTag(new Rect(rowsWidth - childWidth + marginParams.leftMargin, columnHeight + marginParams.topMargin, rowsWidth - marginParams.rightMargin, columnHeight + childHeight - marginParams.bottomMargin));
}
//返回子元素总所占宽度和高度(用于计算Flowlayout的AT_MOST模式设置宽高)
Map<String, Integer> flowMap = new HashMap<>();
//单行
if (aRow) {
flowMap.put("allChildWidth", rowsWidth);
} else {
//多行
flowMap.put("allChildWidth", flowWidth);
}
//FlowLayout测量高度 = 当前行顶部已占高度 +当前行内子元素最大高度+FlowLayout的PaddingBottom
flowMap.put("allChildHeight", columnHeight+rowsMaxHeight+getPaddingBottom());
return flowMap;
}
}
使用
private void SetSearchFlowLayout(SearchFlowLayout searchFlowLayout, List<String> list) {
//往容器内添加TextView数据
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
layoutParams.setMargins(10, 5, 10, 5);
if (searchFlowLayout != null) {
searchFlowLayout.removeAllViews();
}
for (int i = 0; i < list.size(); i++) {
TextView tv = new TextView(this);
tv.setPadding(28, 10, 28, 10);
tv.setText(list.get(i));
tv.setMaxEms(10);
tv.setSingleLine();
tv.setBackgroundResource(R.drawable.shipping_searchflowlayout);
tv.setLayoutParams(layoutParams);
int finalI = i;
tv.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {//最近搜索点击删除
mDbDao.delete(mDbDao.queryData("").get(finalI));
SetSearchFlowLayout(searchShippactivityZjsousuo, mDbDao.queryData(""));//最近搜索
}
});
searchFlowLayout.addView(tv, layoutParams);
}
}
本文地址:https://blog.csdn.net/S__y_p_/article/details/110173580